Universal plating fixture

ABSTRACT

Disclosed are embodiments of a universal electroplating rack and method of using the rack. The universal electroplating rack comprises a main body adapted to accommodate and electrically connect to one or more customized inserts. Each customized insert is adapted to accommodate and electrically connect to a single workpiece. Additionally, both the main body and the customized insert(s) can comprise thief plates configured to improve plating uniformity across the plating surface area of the workpiece(s). Such a universal plating rack ensures a constant plating surface area regardless of workpiece size by varying the dimensions of the customized insert(s) so that universal processing parameters can be used for all workpieces. Consequently, for each new product developed, the universal electroplating racks of the invention will effectively reduce introduction costs, will avoid the need to qualify new electroplating process parameters (e.g., cycle time), and will effectively reduce lead time required.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to electroplating and, more particularly, to anelectroplating rack.

2. Description of the Related Art

Current electroplating processes require customized electroplating racksbe built in order to hold workpieces (e.g., wafers or substrates for aprinted circuit board) during the electroplating process. Such racks arecustomized based on the size of the workpieces, including the length,width and depth, and/or the shape of the workpieces. Additionally, withworkpieces having different sizes or shapes a new thief plate must alsobe built for each workpiece as must new contact devices. Customizingsuch electroplating racks can be time-consuming and costly. Therefore,there is a need in the art for an electroplating rack that can berepeatedly used to hold workpieces with different sizes and/or shapes.

SUMMARY OF THE INVENTION

In view of the foregoing, embodiments of a universal electroplating rackand method of using the universal electroplating rack for repeatedlyholding different workpieces with varying sizes and shapes duringelectroplating processes are disclosed.

Embodiments of the invention avoid building numerous customized platingracks to accommodate workpieces with different sizes and/or shapes byproviding a universal electroplating rack that comprises a main bodyadapted to accommodate and electrically connect to one or morecustomized inserts. Each customized insert is adapted to accommodate andelectrically connect to a single workpiece. Additionally, both the mainbody and the customized insert(s) comprise thief plates configured toimprove plating uniformity across the plating surface area of theworkpiece(s). Such a universal plating ensures a constant platingsurface area regardless of workpiece size by varying the dimensions ofthe customized insert(s) so that universal processing parameters can beused for all workpieces.

More particularly, in one embodiment of the invention (i.e., a singleworkpiece embodiment), the universal plating rack comprises a main bodyand a single customized insert. The main body is adapted to hold andelectrically connect to the customized insert. Specifically, the mainbody comprises a first aperture that extends through the main body fromthe first side to the second side of the rack, a metal surface (i.e., afirst metal surface or thief plate) that surrounds the first aperture onthe first side of the rack and a plurality of first conductors (i.e.,contacts) that protrude into the first aperture at or near the secondside of the rack.

The customized insert is adapted to hold and electrically connect to asingle workpiece and to be inserted into the first aperture of the mainbody. The size and shape of the insert (i.e., the first size and thefirst shape) are customized to conform to the size and shape of thefirst aperture such when the insert is placed in the first aperture, theinsert fits tightly, it contacts the first conductors and the topsurface of the insert is on essentially the same plane as the topsurface of the main body. The customized insert also comprises a secondaperture that extends through the insert and a metal surface (i.e., asecond metal surface or thief plate) that surrounds the second apertureon the first side of the rack. The insert further comprises a pluralityof second conductors (i.e., contacts) that protrude into the secondaperture at or near the second side of the rack. The size and shape ofthe second aperture (i.e., the second size and the second shape) arecustomized to conform to the size and shape of the single workpiece suchthat when the workpiece is placed in the second aperture, the workpiecefits tightly, it contacts the second conductors and the top surface ofthe workpiece is on essentially the same plane as the top surface of theinsert. Thus, the combined top surfaces of the main body, the insert andthe workpiece on the first side of the rack provide a constant andapproximately level surface area to be electroplated so that universalelectroplating processing parameters can be used.

In another embodiment of the invention (i.e., a multiple workpiecesembodiment), the universal plating rack comprises a main body andmultiple customized inserts.

The main body is adapted to hold and electrically connect to each of thecustomized inserts. Thus, in this embodiment the main body comprises notone but a plurality of first apertures that extend through the main bodyfrom the first side to the second side of the rack and a metal surface(i.e., a first metal surface or thief plate) that surrounds each of thefirst apertures on the first side of the rack. The main body furthercomprises a plurality of first conductors (i.e., contacts) that protrudeinto each of the first apertures at or near the second side of the rack.

The customized inserts are each adapted to hold and electrically connectto a corresponding workpiece and to be inserted into one of the firstapertures of the main body. The outer dimensions of the inserts (i.e.,the first sizes and first shapes) are customized to conform to the firstapertures such that when the inserts are placed in the first apertures,the inserts fit tightly, the inserts contact the first conductors andthe top surfaces of the inserts are on essentially the same plane as thetop surface of the main body. Additionally, the first apertures can allbe equal in size and shape such that all of the customized inserts willhave the same outer dimensions. Each of these customized inserts alsocomprises a second aperture that extends through the insert and a metalsurface (i.e., a second metal surface or thief plate) that surrounds thesecond aperture on the first side of the rack. The customized insertscan each further comprise a plurality of second conductors (i.e.,contacts) that protrude into the second aperture at or near the secondside of the rack. The size and shape of the second aperture (i.e., thesecond size and the second shape) for each of the inserts are customizedto conform to specific corresponding workpieces such that when thecorresponding workpieces are placed in the second apertures, theworkpieces fit tightly, they contact the second conductors and the topsurfaces of the workpieces are on essentially the same plane as the topsurfaces of the inserts. Thus, the combined top surfaces of the mainbody, the inserts and the workpieces on the first side of the rackprovide a constant and approximately level surface area to beelectroplated so that universal electroplating processing parameters canbe used.

An embodiment of the method of electroplating a single workpiece using auniversal electroplating rack comprises first providing a main body forthe universal electroplating rack. The main body comprises a firstaperture, a plurality of first conductors that protrude into the firstaperture and a metal surface (i.e., a first metal surface or first thiefplate) surrounding the first aperture on the first side of the rack.Then, an insert is customized, as needed, for each specific workpiecethat is to be electroplated using the universal electroplating rack.Specifically, an insert is formed with a size and shape that conforms toa size and a shape of the first aperture so that the insert can fitwithin the first aperture and can contact the first conductors. Theinsert is also formed with a second aperture that has a customized sizeand shape (i.e., a second size and a second shape), a plurality ofsecond conductors that protrude into the second aperture (e.g., at ornear the second side of the rack) and a metal surface (i.e., a secondmetal surface or thief plate) surrounding the second aperture.Specifically, this thief plate of the insert surrounds the secondaperture on the first side of the rack when the insert is positionedwithin the first aperture. The size and shape of the second aperture arecustomized to conform to the size and shape of the specific workpiece tobe electroplated so that the workpiece can fit within the secondaperture and contact the second conductors. Additionally, the insert iscustomized so that when the specific workpiece is inserted into secondaperture of the insert and the insert is inserted into the firstaperture of the main body, the combined surfaces of the main body, theinsert and the workpiece on the first side of the rack provide aconstant and approximately level surface area to be electroplated. Dueto this constant surface area, workpieces with different sizes andshapes that are electroplated using the same main body with a customizedinsert can be electroplated by applying universal plating parameters(i.e., by applying the same plating parameters).

An embodiment of the method of simultaneously electroplating multipleworkpieces using a universal electroplating rack, as described above,comprises first providing a main body for the universal electroplatingrack. The main body can comprise multiple first apertures. Thesemultiple first apertures can each have the same size and shape. The mainbody can also comprise a plurality of first conductors that protrudeinto each of the first apertures and a metal surface (i.e., a firstmetal surface or first thief plate) on a first side of the racksurrounding the first apertures. Then, inserts are customized, asneeded, for each of the workpieces that are to be simultaneouslyelectroplated using the universal electroplating rack. Specifically,each insert is formed with a size and shape (i.e., first size and afirst shape) that conforms to the size and shape of a first aperture sothat each insert can fit within a first aperture and can contact thefirst conductors. Note that, as mentioned above, the first apertures caneach have the same size and shape such that the multiple inserts areeach formed with the same size and shape (i.e., the same first size andsame first shape) and can fit within any of the first apertures. Eachinsert is also formed with a second aperture that has a customized sizeand shape (i.e., a second size and a second shape), a plurality ofsecond conductors that protrude into the second aperture (e.g., at ornear the second side of the rack), and a metal surface (i.e., a secondmetal surface or thief plate) that surrounds the second aperture.Specifically, the thief plate of each insert surrounds the secondaperture on the first side of the rack when the insert is positionedwithin a first aperture. For each of the customized inserts, the sizeand shape of the second aperture are customized to conform to the sizeand shape of a corresponding specific workpiece so that thecorresponding workpiece can fit within the second aperture and contactthe second conductors. Additionally, each insert is customized so thatwhen a each corresponding workpiece is inserted into the second apertureof its insert and the inserts are inserted into the first apertures ofthe main body, the combined surfaces of the main body, the inserts andthe workpieces on the first side of the rack provide a constant andapproximately level surface area to be electroplated. Due to thisconstant surface area, these workpieces with different sizes and shapesthat are simultaneously electroplated using the same main body with acustomized inserts can be electroplated by applying universal platingparameters (i.e., by applying the same plating parameters).

These, and other, aspects and objects of the present invention will bebetter appreciated and understood when considered in conjunction withthe following description and the accompanying drawings. It should beunderstood, however, that the following description, while indicatingembodiments of the present invention and numerous specific detailsthereof, is given by way of illustration and not of limitation. Manychanges and modifications may be made within the scope of the presentinvention without departing from the spirit thereof, and the inventionincludes all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood from the following detaileddescription with reference to the drawings, in which:

FIG. 1 is a diagram illustrating a top view of an exemplary embodimentof the universal plating rack of the invention;

FIG. 2 is a diagram illustrating a bottom view of the rack of FIG. 1;

FIG. 3 is a diagram illustrating a top view of an exemplary customizedinsert;

FIG. 4 is a diagram illustrating a bottom view of the insert of FIG. 5;

FIG. 5 is a diagram illustrating a top view of another exemplaryembodiment of the universal plating rack of the invention;

FIG. 6 is a diagram illustrating a bottom view of the rack of FIG. 3;

FIG. 7 is a flow diagram illustrating an embodiment of the method of theinvention; and

FIG. 8 is a flow diagram illustrating another embodiment of the methodof the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The present invention and the various features and advantageous detailsthereof are explained more fully with reference to the nonlimitingembodiments that are illustrated in the accompanying drawings anddetailed in the following description. It should be noted that thefeatures illustrated in the drawings are not necessarily drawn to scale.Descriptions of well-known components and processing techniques areomitted so as to not unnecessarily obscure the present invention. Theexamples used herein are intended merely to facilitate an understandingof ways in which the invention may be practiced and to further enablethose of skill in the art to practice the invention. Accordingly, theexamples should not be construed as limiting the scope of the invention.

As mentioned above, current electroplating process flows require thebuilding of a plating rack for each product based on product size. Withthe different-sized products, there is also a need to build a new thiefplate and different-sized contact devices. Thus, differentelectroplating process parameters are required for each design.Consequently, current electroplating process flow necessitates addedcost, as new products are introduced. Therefore, disclosed is auniversal electroplating rack and method of using the rack.Specifically, a single rated plating rack is used and inserts arecustomized for each product size electroplated. The thief plate isincorporated into the insert as are contact devices, making the rack andprocess plating parameters universal. Additionally, a variety ofuniversal inserts can be formed for to accommodate same-sized products.

More particularly, embodiments of a universal electroplating rack andmethod of using the universal electroplating rack for repeatedly holdingdifferent workpieces with varying sizes and shapes during electroplatingprocesses are disclosed. These embodiments of the invention avoidbuilding numerous customized plating racks to accommodate workpieceswith different sizes and/or shapes by providing a universalelectroplating rack that comprises a main body adapted to accommodateand electrically connect to one or more customized inserts. Eachcustomized insert is adapted to accommodate and electrically connect toa single workpiece. Additionally, both the main body and the customizedinsert(s) comprise thief plates configured to improve plating uniformityacross the plating surface area of the workpiece(s). Such a universalplating rack ensures a constant plating surface area regardless ofworkpiece size by varying the dimensions of the customized insert(s) sothat universal processing parameters can be used for all workpieces.

FIGS. 1 and 2 illustrate a top view (i.e., first side 101) and a bottomview (i.e., second side 102), respectively, of a universal plating rack100 that holds a single workpiece 140 (e.g., a wafer, a substrate,etc.). The universal plating rack 100 comprises a main body 105 and acustomized insert 110.

The main body 105 is adapted to hold a customized insert 110 and toelectrically connect to that customized insert 110. Specifically, themain body 105 comprises a first aperture 120 that extends through themain body 105 from the first side 101 to the second side 102 of the rack100 and a metal surface 106 (i.e., a first metal surface or thief plate,such as a stainless steel frame) that surrounds the first aperture 120particularly on the first side 101 of the rack 100. The main body 105further comprises a plurality of first conductors 107 that protrude intothe first aperture 120 at or near the second side 102 of the rack 100.These first conductors 107 can comprise metal contact devices thatelectrically connect the customized insert 110 to the main body 105 andcan be formed either integral with or attached to the main body 105.

The customized insert 110 is adapted to be inserted into the firstaperture 120 of the main body 105 such that the top surface of theinsert 110 is essentially on the same plane as the top surface of themain body 105, to hold a single workpiece 140 such that the top surfaceof the workpiece 140 is essentially on the same plane as the top surfaceof the insert 110, and to electrically connect to the single workpiece140. FIGS. 3 and 4, respectively, illustrate a top view (i.e., a firstside 101) and a bottom view (i.e., a second side 102) of an exemplarycustomized insert 110. Specifically, the customized insert 110 cancomprise a second aperture 130 that extends through the insert 110(e.g., from the first side 101 of the rack 100 to the second side 102when the insert 110 is placed within the first aperture 120) and a metalsurface 111 (i.e., a second metal surface or thief plate, such as astainless steel frame) that surrounds the second aperture 130,particularly, on the first side 101 of the rack 100. The customizedinsert 110 can also comprise a plurality of second conductors 112 thatprotrude into the second aperture 130 at or near the second side 102 ofthe rack 100. These second conductors 112 can comprise contact devicesthat electrically connect the workpiece 140 to the customized insert 110and can be formed either integral with, or attached to the insert 110.

Each new insert 110 is customized for each new product with a differentsize or shape, while the main body 105 of the rack 100 remains unchangedwith repeated uses. Therefore, for each new customized insert 110 for aparticular universal rack 100, the outer dimensions of the insert 110(i.e., the first size, including length 411, width 412 and depth 413(see FIG. 4), and the first shape) are the same. Specifically, the sizeand shape of each new insert 110 (i.e., the first size and the firstshape) are customized to conform to the size and shape of the firstaperture 120 such that when the insert 110 is placed in the firstaperture 120, the insert 110 fits tightly, it contacts the firstconductors 107 at or near the second side 102 of the rack 100 and thetop surface of the insert 110 is essentially on the same plane as thetop surface of the main body 105 on the first side 101 of the rack 100.

However, other dimensions of the insert 110 can vary for each product(i.e., a workpiece, such as a substrate or wafer) in order to hold theworkpiece 140, electrically connect the workpiece 140 to the insert 110and to ensure a constant and approximately level surface area forelectroplating regardless of the size/shape of the workpiece 140 so thatuniversal electroplating processing parameters may be used.Specifically, the size and shape of the second aperture 130 (i.e., thesecond size and the second shape) are customized to conform to the sizeand shape of the workpiece 140 such that when the workpiece is place inthe second aperture 130, the workpiece 140 fits tightly, it contacts thesecond conductors 112 at or near the second side 102 of the rack 100,and the top surface of the workpiece 140 is essentially on the sameplane as the top surface of the insert 110 on the first side 101 of therack 100. Thus, referring to FIG. 4, the following insert dimensions mayvary. The size (e.g., the length 404, width 405, etc.) and shape of thesecond aperture 130 (e.g., a square (as shown), a rectangle, a circle,etc.) may vary in order to receive a similarly sized and shapedworkpiece 140. The position and size, including the length 406 and width408, of the second conductors 112 may vary in order to electricallyconnect the workpiece 140 to the insert 110. Furthermore, the depth 403of the second conductors 112 within the second aperture 130 may vary inorder to ensure that when the workpiece 140 is placed in the insert 110,the top surface of the workpiece 140 is positioned essentially on thesame plane as the top surface of the insert 110 on the first side 101 ofthe rack. Thus, by varying the dimensions of the insert 110, a user canensure that the combined top surfaces of the main body, the insert andthe workpiece on the first side 101 of the rack 100 provide a constantand approximately level surface area to be electroplated so thatuniversal electroplating processing parameters can be used.Specifically, regardless of the size and/or shape of the product beingplated, the current will not need to be changed to maintain the sameplating rate (Amps/cm²) because the Current/Surface Area=Plating Rate.Higher currents (i.e. plating rates), are more likely to disrupt theelectric field, causing turbulence and erratic plating.

FIGS. 5 and 6 illustrate a top view (i.e., first side 501) and a bottomview (i.e., second side 502), respectively, of a universal plating rack500 that holds multiple workpieces 540 (e.g., wafers, substrates, etc.)that may have different sizes and/or shapes (e.g., see workpieces 540 aand 540 b). The universal plating rack 500 comprises a main body 505 anda multiple customized inserts 510 to accommodate the workpieces 540 withdifferent sizes and/or shapes.

The main body 505 is adapted to hold the customized inserts 510 and toelectrically connect to those customized inserts 510. Specifically, themain body 505 comprises multiple first apertures 520 that extend throughthe main body 505 from the first side 501 to the second side 502 of therack 500 and a metal surface 506 (i.e., a first metal surface or thiefplate, such as a stainless steel frame) that surrounds the firstapertures 520 particularly on the first side 501 of the rack 500. Themain body 505 further comprises a plurality of first conductors 507 thatprotrude into the first apertures 520 at or near the second side 502 ofthe rack 500. These first conductors 507 can comprise metal contactdevices that electrically connect the customized inserts 410 to the mainbody 505 and can be formed either integral with or attached to the mainbody 505.

Each of the customized inserts 510 is adapted to be inserted into afirst aperture 520 of the main body 505 such that the top surface of theinsert 510 is essentially on the same plane as the top surface of themain body 505, to hold a specific workpiece (e.g., 540 a, 540 b, etc.)such that the top surface of that specific workpiece is essentially onthe same plane as the top surface of the insert 510, and to electricallyconnect to the that workpiece. As with the previously describedembodiment, FIGS. 3 and 4, respectively, illustrate a top view (i.e., afirst side 501) and a bottom view (i.e., a second side 502) of anexemplary customized insert 510. Specifically, each of the customizedinserts 510 can comprise a second aperture 530 that extends through theinsert 510 (e.g., from the first side 501 of the rack 500 to the secondside 502 when the insert 510 is placed within the first aperture 520)and a metal surface 511 (i.e., a second metal surface or thief plate,such as a stainless steel frame) that surrounds the second aperture 530,particularly, on the first side 501 of the rack 500. Each of thecustomized inserts 510 can also comprise a plurality of secondconductors 512 that protrude into the second aperture 530 at or near thesecond side 502 of the rack 500. These second conductors 512 cancomprise metal contact devices that electrically connect the specificworkpiece (e.g., 540 a, 540 b, etc.) to the customized insert 510 andcan be formed either integral with or attached to the insert 510.

Each insert 510 is customized for each new product having a differentsize or shape, while the main body 505 of the rack 500 remains unchangedwith repeated uses. If the sizes and shapes of the first apertures 520are all equal, all of the customized inserts 510 will have the samefirst size and the same first shape (i.e., the same outer dimensions).Specifically, if the first apertures 520 are symmetric, for eachcustomized insert 510 for a particular universal rack 500, the outerdimensions of the insert 510 (i.e., the first size, including length411, width 412 and depth 413 (see FIG. 4), and the first shape). Theseouter dimensions conform to the size and shape of the first apertures520 such that when the inserts 510 are placed in the first apertures520, the inserts 510 fit tightly, they contact the first conductors 507at or near the second side 502 of the rack 500 and the top surfaces ofthe inserts 510 are essentially on the same plane as the top surface ofthe main body 505 on the first side 501 of the rack 500.

However, other dimensions of the inserts (e.g., inserts 510 a, 510 b,etc.) can vary for each product (e.g., substrate or wafer) to beelectroplated (i.e., each workpiece 540 a, 540 b, etc.) in order to holdthe multiple workpieces 540, electrically connect the workpieces 540 tothe inserts 510 and to ensure a constant and approximately level surfacearea for electroplating regardless of the varying sizes and/or shapes ofthe workpieces 540 so that universal electroplating processingparameters may be used. Specifically, the size and shape of the secondaperture 530 of each insert (e.g., 510 a, 510 b, etc.) are customized toconform to the size and shape of specific workpieces (e.g., 540 a, 540b, etc.) such that when the workpieces are place in the second apertures530, they fit tightly, they contact the second conductors 512 at or nearthe second side 502 of the rack 500, and the top surfaces of theworkpieces 540 are essentially on the same plane as the top surface ofthe inserts 510 on the first side 101 of the rack 100. Thus, referringto FIG. 4, the following insert dimensions may vary. The size, includingthe length 404 and width 405 (e.g., see the second apertures 530 a and530 b of FIG. 5) and shape of the second apertures 530 (e.g., a square(as shown), a rectangle, a circle, etc.) may vary in order to receive asimilarly sized and shaped workpiece 540. The position and size,including the length 406 and width 408, of the second conductors 512 mayvary in order to electrically connect the workpieces 540 to the inserts510. Furthermore, the depth 403 of the second conductors 512 within thesecond aperture 530 of each insert 510 may vary in order to ensure thatwhen the workpieces 540 are placed in the inserts 510, the top surfacesof the workpieces 540 are positioned essentially on the same plane asthe top surfaces of the inserts 510 on the first side 501 of the rack500. Thus, by varying the dimensions of the inserts 510, a user canensure that the combined top surfaces of the main body 505, the inserts510 and the workpieces 540 on the first side 501 of the rack 500 providea constant and approximately level surface area to be electroplated sothat universal electroplating processing parameters can be used.Specifically, regardless of the size and/or shape of the product beingplated, the current will not need to be changed to maintain the sameplating rate (Amps/cm²) because the Current/Surface Area=Plating Rate.Higher currents (i.e. plating rates), are more likely to disrupt theelectric field, causing turbulence and erratic plating.

Referring to FIG. 7, an embodiment of the method of electroplating asingle workpiece using a universal electroplating rack 100, as describedabove and illustrated in FIGS. 1-2, comprises first providing a mainbody 105 for the universal electroplating rack 100 (702). The main body105 should comprise a first aperture 120 (704), a plurality of firstconductors 107 that protrude into the first aperture 120 (708) and ametal surface 106 (i.e., a first metal surface or first thief plate)surrounding the first aperture 120 on the first side 101 of the rack 100(710).

Then, an insert 110 is customized (712), as needed, for each specificworkpiece 140 that is to be electroplated using the universalelectroplating rack 100. Specifically, an insert 110 is formed with asize and shape (i.e., first size and a first shape) that conforms to asize and a shape of the first aperture 120 so that the insert 110 canfit within the first aperture and can contact the first conductors 107(714). The insert 110 is also formed with a second aperture 130 (716)that has a customized size and shape (i.e., a second size and a secondshape), a plurality of second conductors 112 that protrude into thesecond aperture 130 (e.g., at or near the second side 102 of the rack100) (720) and a metal surface 111 (i.e., a second metal surface orthief plate) surrounding the second aperture 120 (721). Specifically,this thief plate 106 of the insert 110 surrounds the second aperture 120on the first side 101 of the rack 100 when the insert 110 is positionedwithin the first aperture 120. The size and shape of the second aperture130 are customized to conform to the size and shape of the specificworkpiece 140 to be electroplated so that the workpiece 140 can fitwithin the second aperture 130 and contact the second conductors 112(718).

Additionally, the insert 110 is customized so that when the specificworkpiece 140 is inserted into second aperture 130 of the insert 110 andthe insert 110 is inserted into the first aperture 130 of the main body105 (at process 724), the combined surfaces of the main body 105, theinsert 110 and the workpiece 140 on the first side 101 of the rack 100provide a constant and approximately level surface area to beelectroplated (722). The electroplating process can then proceed asfollows. The universal plating rack 100 is placed in a plating tankcontaining a plating solution having conventional components (e.g.,copper, silver, etc.) for the type of metal and features to beelectroplated. Also placed in the plating tank is an anode. A powersupply is connected between the anode and the universal rack, which actsas a cathode. As current flows between the anode and cathode, metallicfeatures are plated onto the top surface of the workpiece 140 and thesurrounding thief plates 106, 111 of the insert 110 and the main body105. Due to the constant surface area formed at process 722, workpieces140 with different sizes and shapes that are electroplated using thesame main body 105 with different customized inserts can beelectroplated by applying universal plating parameters (i.e., byapplying the same plating parameters) (726). Specifically, regardless ofthe size and/or shape of the product being plated, the current will notneed to be changed to maintain the same plating rate (Amps/cm²) becausethe Current/Surface Area=Plating Rate. Higher currents (i.e. platingrates), are more likely to disrupt the electric field, causingturbulence and erratic plating.

Referring to FIG. 8, an embodiment of the method of simultaneouslyelectroplating multiple workpieces using a universal electroplating rack500, as described above and illustrated in FIGS. 5-6, comprises firstproviding a main body 505 for the universal electroplating rack 500(802). The main body 505 can comprise multiple first apertures 520(804). These multiple first apertures 520 can each have the same sizeand shape (806). The main body 505 can also comprise a plurality offirst conductors 507 that protrude into each of the first apertures 530(808) and a metal surface 506 (i.e., a first metal surface or firstthief plate) on a first side 501 of the rack 500 surrounding the firstapertures 530 (810).

Then, inserts 510 are customized, as needed, for each of the workpieces540 that are to be simultaneously electroplated using the universalelectroplating rack 500 (812). Specifically, each insert 510 is formedwith a size and shape (i.e., first size and a first shape) that conformsto the size and shape of a first aperture 520 so that each insert 510can fit within a first aperture 520 and can contact the first conductors507 (814). Note that if the first apertures 520 each have the same sizeand shape, then the multiple inserts 510 are each formed with the samesize and shape (i.e., the same first size and same first shape) and canfit within any of the first apertures (815). Each insert 510 is alsoformed with a second aperture 530 that has a customized size and shape(i.e., a second size and a second shape) (816), a plurality of secondconductors 512 that protrude into the second aperture 530 (e.g., at ornear the second side 502 of the rack 500) (820), and a metal surface 511(i.e., a second metal surface or thief plate) that surrounds the secondaperture (821). Specifically, the thief plate 511 of each insertsurrounds the second aperture 530 on the first side 501 of the rack 500when the insert 510 is positioned within a first aperture 520. For eachof the customized inserts 510, the size and shape of the second aperture530 are customized to conform to the size and shape of a correspondingspecific workpiece (e.g., 540 a, 540 b, etc.) so that the correspondingworkpiece can fit within the second aperture (e.g., 530 a, 530 b, etc.)and contact the second conductors 512 (818).

Additionally, each insert 510 is customized so that when eachcorresponding workpiece (9e.g., 540 a, 540 b, etc.) is inserted into asecond aperture (e.g., 530 a, 530 b, etc.) of an insert 510 and theinserts 510 are inserted into the first apertures 520 of the main body505 (at process 824), the combined surfaces of the main body 505, theinserts 510 and the workpieces 540 on the first side 501 of the rack 500provide a constant and approximately level surface area to beelectroplated (822). The electroplating process can then proceed asfollows. The universal plating rack 500 is placed in a plating tankcontaining a plating solution having conventional components (e.g.,copper, silver, etc.) for the type of metal and features to beelectroplated. Also placed in the plating tank is an anode. A powersupply is connected between the anode and the universal rack, which actsas a cathode. As current flows between the anode and cathode, metallicfeatures are plated onto the top surfaces of the workpieces 540 and thesurrounding thief plates 506, 511 of the inserts 510 and the main body505. Due to the constant surface area formed at process 822, theseworkpieces 540 with different sizes and shapes that are simultaneouslyelectroplated using the same main body 505 with customized inserts 510can be electroplated by applying universal plating parameters (i.e., byapplying the same plating parameters) (826). Specifically, regardless ofthe size and/or shape of the product being plated, the current will notneed to be changed to maintain the same plating rate (Amps/cm²) becausethe Current/Surface Area=Plating Rate. Higher currents (i.e. platingrates), are more likely to disrupt the electric field, causingturbulence and erratic plating.

Therefore, the embodiments of the invention disclosed above avoidbuilding numerous customized plating racks to accommodate workpieceswith different sizes and/or shapes by providing a universalelectroplating rack. The universal plating rack comprises a main bodyadapted to accommodate and electrically connect to one or morecustomized inserts. Each customized insert is adapted to accommodate andelectrically connect to a single workpiece. Additionally, both the mainbody and the customized insert(s) comprise thief plates configured toimprove plating uniformity across the plating surface area of theworkpiece(s). Such a universal plating rack ensures a constant platingsurface area regardless of workpiece size by varying the dimensions ofthe customized insert(s) so that universal processing parameters can beused for all workpieces. Consequently, for each new product developed,the universal electroplating racks of the invention will effectivelyreduce introduction costs, will avoid the need to qualify newelectroplating process parameters (e.g., cycle time), and willeffectively reduce lead time required. Additionally, the universalplating racks of the invention will allow experiments to be conductedmore easily for possible future products. While the invention has beendescribed in terms of embodiments, those skilled in the art willrecognize that the invention can be practiced with modification withinthe spirit and scope of the appended claims.

1. A rack for holding, during an electroplating process, a workpiece,said rack comprising: a main body comprising a first aperture and aplurality of first conductors that protrude into said first aperture; aninsert comprising a second aperture and a plurality of second conductorsthat protrude into said second aperture, wherein a first size and afirst shape of said insert conform to said first aperture such that saidinsert fits within said first aperture and contacts said firstconductors, and wherein a second size and a second shape of said secondaperture conform to said workpiece such that said workpiece fits withinsaid second aperture and contacts said second conductors.
 2. The rack ofclaim 1, wherein combined surfaces of said main body, said insert andsaid workpiece on a first side of said rack provide a constant surfacearea to be electroplated.
 3. The rack of claim 1, wherein combinedsurfaces of said main body, said insert and said workpiece on a firstside of said rack provide an approximately level surface area to beelectroplated.
 4. The rack of claim 1, wherein said main body furthercomprises a first metal surface adjacent to said first aperture on afirst side of said rack and said insert further comprises a second metalsurface adjacent to said second aperture.
 5. A rack for holding, duringan electroplating process, a plurality of workpieces, said rackcomprising: a main body comprising a plurality of first apertures and aplurality of first conductors that protrude into each of said firstapertures; and a plurality of inserts, wherein said inserts eachcomprise a second aperture and a plurality of second conductors thatprotrude into said second aperture, wherein said inserts each comprise afirst size and a first shape that conform to said first apertures suchthat said inserts fit within said first apertures and contact said firstconductors, and wherein for each of said inserts, said second aperturecomprises a second size and a second shape that conform to acorresponding one of said workpieces such that said corresponding one ofsaid workpieces fits within said second aperture and contacts saidsecond conductors.
 6. The rack of claim 5, wherein all of said firstapertures are equal in size and shape such that all of said inserts havea same first size and a same first shape.
 7. The rack of claim 5,wherein combined surfaces of said main body, said inserts, and each ofsaid workpieces on a first side of said rack provide a constant surfacearea to be electroplated.
 8. The rack of claim 5, wherein combinedsurfaces of said main body, said inserts, and each of said workpieces ona first side of said rack provide an approximately level surface area tobe electroplated.
 9. The rack of claim 5, wherein said main body furthercomprises a first metal surface adjacent to said first apertures on afirst side of said rack and each of said inserts further comprise asecond metal surface adjacent to said second aperture.
 10. A method ofelectroplating a workpiece using a universal electroplating rack, saidmethod comprising: providing a main body of said universalelectroplating rack such that said main body comprises a first apertureand a plurality of first conductors that protrude into said firstaperture; and customizing an insert for said universal electroplatingrack such that said insert is formed with the following: a first sizeand a first shape that conform to said first aperture so that saidinsert can fit within said first aperture and contact said firstconductors, a second aperture having second size and a second shape, anda plurality of second conductors that protrude into said secondaperture, wherein said second size and said second shape conform to saidworkpiece so that said workpiece can fit within said second aperture andcontact said second conductors.
 11. The method of claim 10, wherein saidcustomizing further comprises customizing said insert such that whensaid workpiece is inserted into said insert and said insert is insertedinto said main body, combined surfaces of said main body, said insertand said workpiece on a first side of said universal electroplating rackprovide a constant surface area to be electroplated.
 12. The method ofclaim 10, wherein said customizing further comprises customizing saidinsert such that when said workpiece is inserted into said insert andsaid insert is inserted into said main body, combined surfaces of saidmain body, said insert and said workpiece on a first side of saiduniversal electroplating rack provide an approximately level surfacearea to be electroplated.
 13. The method of claim 10, wherein said mainbody is further provided with a first metal surface adjacent to saidfirst aperture on a first side of said universal electroplating rack andwherein said customizing further comprises forming said insert with asecond metal surface adjacent to said second aperture.
 14. The method ofclaim 10, further comprising electroplating said workpiece by applyinguniversal plating parameters.
 15. A method of electroplating a pluralityof workpieces using a universal electroplating rack, said methodcomprising: providing a main body of said universal electroplating racksuch that said main body comprises a plurality of first apertures and aplurality of first conductors that protrude into said first apertures;and customizing a plurality of inserts for said universal electroplatingrack such that each of said inserts is formed with the following: afirst size and a first shape that conforms to at least one of said firstapertures such that said inserts can fit within said first apertures andcontact said first conductors, a second aperture that has a second sizeand a second shape, and a plurality of second conductors that protrudeinto said second aperture, wherein said second size and said secondshape conform to a corresponding one of said workpieces so that saidcorresponding one of said workpieces can fit within said second apertureand contact said second conductors.
 16. The method of claim 15, whereinall of said first apertures are formed equal in size and shape.
 17. Themethod of claim 15, wherein said customizing further comprisescustomizing said inserts such that when said workpieces are insertedinto said inserts and said inserts are inserted into said main body,combined surfaces of said main body, said inserts and said workpieces ona first side of said universal electroplating rack provide a constantsurface area to be electroplated.
 18. The method of claim 15, whereinsaid customizing further comprises customizing said inserts such thatwhen said workpieces are inserted into said inserts and said inserts areinserted into said main body, combined surfaces of said main body, saidinserts and each of said workpieces on a first side of said universalelectroplating rack provide an approximately level surface area to beelectroplated.
 19. The method of claim 15, wherein said main body isfurther provided with a first metal surface adjacent to said firstapertures on a first side of said universal electroplating rack andwherein said customizing further comprises forming each of said insertswith a second metal surface adjacent to said second aperture.
 20. Themethod of claim 15, further comprising simultaneously electroplatingsaid workpieces by applying universal plating parameters.